THE PYRAMID 41
a winter's careful surveying work at the Pyramids, found seventy-one inches difference between his figure and that of Piazzi Smyth of the most important measurement in the edifice. I know, finally, another man, a trained engineer, who lately re-examined all the external and internal dimensions of the Great Pyramid, as presented not only by Piazzi Smyth, but also by his chief modern successors, and found to be unreliable several of the computations given by the latter gentlemen. Indeed, Petrie tells an amusing story of his discovery of a
SECTIONAL PLAN OF THE GREAT PYRAMID'S INTERIOR
Dinted follower of Smyth's, whom he found trying to file "down the granite boss in the ante-room to the King's Chamber to the size required for the theory!
But the weakness of their figures is not the only reason why one must be a little wary about going whither these enthusiastic people would lead us. Many years ago they used to give 2170 B.C. as the date of the Pyramid's construction, because in that year a certain Pole Star was in a straight line with the axis of the entrance passage, and they thought that this long dark passage had been set at an angle which would catch the light of this star. But, owing to that grand movement in the heavens called precession of equinoxes, the stars move from their original